1. Field of the Invention
This invention is related to computer telephony integration. In particular, this invention relates to a unified way of managing incoming calls, whether they arrive via internet telephony or the public switched telephone network (PSTN). Using this invention a computer user can choose, either in advance or in real time, to receive calls in various ways regardless of whether the call is coming in via the PSTN or via a multimedia data connection.
2. Description of the Problem Solved
Until recently, voice telecommunications and data telecommunications have been largely separate to most computer users. Increasingly, computer users run applications which include integrated multimedia communications. These systems generally include voice capability, where the voice communication path is terminated by the user""s personal computer. Such a system makes use of voice data conversion such as voice-over-internet protocol or internet telephony. However, for reasons of voice quality, service availability, and compatibility, most users also maintain standard telephone customer premises equipment (CPE) for use with the PSTN.
Integration between data and high quality PSTN voice is highly desirable. A system which provides integration between multimedia telephony applications and high-quality PSTN voice services is described in patent application Ser. No. 065,124, filed Apr. 23, 1998, entitled xe2x80x9cIntegrated Telecommunication Collaboration System,xe2x80x9d which is assigned to the assignee of the present invention, and which is incorporated herein by reference. The system described in the patent application allows high-quality PSTN voice communications to work together with multimedia data communications to provide integrated collaboration between parties from within desktop applications. However, audio is always handled via a PSTN connection in a collaborative or harmonized call, and any PSTN audio is always received through a PSTN telephone. What is needed is a way to provide users with the ability to choose to handle any kind of incoming call either through a standard PSTN telephone, or through a headset or handset which is connected to a multimedia data communications client.
The present invention solves the above problems by allowing users to control incoming PSTN and multimedia internet telephony calls in a consistent manner. The invention allows users to use multiple devices together during a call or set of calls. The invention can monitor the media channels being used within a call and route them to separate devices appropriate for the type of media to be passed. Users can specify whether they wish to receive calls over their PSTN phone only, telephony client software on a workstation only, or some combination, regardless of whether the incoming call originated via an Internet telephony client or through the PSTN. The distinction of whether the calls are from a telephony client or the PSTN telephone is hidden from the user, thus providing a consistent mechanism for incoming call management. The invention also addresses the situation where a user has combination of voice terminals and data terminals and wants the flexibility to use multiple devices in a single call.
The invention works by either re-routing a public switched telephone network call to a user multimedia client which handles multimedia data calls with an audio portion, or re-routing the audio portion of multimedia data call from a network multimedia client to a user""s PSTN telephone. In the preferred embodiment, the invention is implemented by a call processor, a gateway, and a user proxy, all disposed near the user. The system is connected to a PSTN switch which includes a computer telephony interface. In order to route to a PSTN call to user multimedia client capable of handling multimedia calls with an audio portion, the system described above first receives a call offered notification and checks for routing instructions from the user. The system then sends a redirect call request and an alerting message to the PSTN switch. Finally the system connects the PSTN call as the audio portion while the multimedia call being received by the user multimedia client. The routing instructions can be stored in the user proxy, or can be specified in real-time by the user.
In the case where a call is being placed by a multimedia data client in the network to the user, the system determines routing instructions as described above, and routes the audio portion of the call to the users PSTN telephone if required. The system first must establish a location and a destination number for the telephone. The system then establishes a PSTN audio connection between the network multimedia client and the user PSTN telephone. Since the call is being originated by a multimedia data client in the network, in most cases the call also has data portion, which must be transferred to the user multimedia client. In addition to the scenarios described above, an audio portion of a call can be switched mid-stream by detection of an off-hook notification.
The invention is deployed in the network which includes apparatus for handling multimedia calls. Such multimedia call has an audio portion and a data portion. The network includes a PSTN switch which has a computer telephony interface. A plurality of user devices are disposed at the user location, including a telephone connected to the PSTN switch. The call processor, gateway, and a user proxy in most cases, are connected to each other and to at least some of the user devices via a local area network. The gateway is typically connected to the PSTN switch.
The software which implements many aspects of the present invention can be stored on a media. The media can be magnetic such as diskette, tape or fixed disk, or optical such as a CD-ROM. Additionally, the software can be supplied via the Internet or some type of private data network. Workstations which typically run the client software include a plurality of input/output devices, a connection for a network and a system unit which includes both hardware and software necessary make the invention work.